Technological advancements in refrigeration appliances such as refrigerators have led to rapid progress in the field of refrigeration compressors. With increasing demands for environmental protection and energy conservation, refrigerator manufacturers have increased their efforts in developing energy efficient chlorofluorocarbon (CFC) free refrigerators. Therefore it is necessary for the refrigerator compressor industry to explore new products in order to keep pace with the progress in the refrigerator industry.
Existing refrigerator compressors have a reciprocating piston construction. FIG. 1 shows the structure of a typical refrigeration compressor of a refrigerator. The compressor mainly includes a compressor housing 1, a compressor cylinder block 2, a piston rod 3, a crankshaft 4, an exhaust muffler chamber 5, a compressor cylinder cover 6, a valve plate 7, an intake muffler chamber, an electric motor, and other components. The exhaust muffler chamber 5 is casted onto the compressor cylinder block 2. Compressed gas from the compressor passes through a gas flow passage in the valve plate 7, through the compressor cylinder cover 6, into an exhaust gas flow passage in the compressor cylinder block 2, then is expended and enters the exhaust muffler chamber 5 to reduce the pressure of exhaust gas, and to moderate the high pressure flow of the compressed gas to reduce a noise level from the compressor.
However when the above compressor operates, the temperature and pressure of the compressed gas increases as a result of being compressed (temperature reaching 160° C.±, pressure reaching 32 kg). When the high-temperature-high-pressure gas flows through the exhaust muffler chamber 5, it transfers heat to the exhaust muffler chamber 5. Since the traditional exhaust muffler chamber 5 is casted onto the compressor cylinder block 2, heat is retained at the compressor cylinder block 2, cannot be dissipated outside of the compressor. Due to the heat retained inside the compressor, the compressor cylinder block 2 becomes a heating source. In addition to the heat produced by gas compression, heat is also produced by the electric motor during operation. As a result the temperature inside the compressor can be extremely high, and incoming gas is heated by heating sources inside the compressor. The extremely high temperature of incoming gas lowers the gas density, and thereby reduces the mass of incoming gas and the amount of compressed gas produced by the compressor. This leads to a reduction in the mass of output refrigerant. Thus, the compressor may consume a large amount of energy but deliver poor cooling performance.
FIG. 2 illustrates another exhaust muffler device for an existing refrigeration compressor. The exhaust muffler device includes an ellipsoidal exhaust buffer chamber 11. The exhaust buffer chamber 11 is located outside the compressor cylinder block and is connected to the compressor cylinder block via a pipe. The exhaust buffer chamber 11 is formed by rotating and extruding a copper pipe and the manufacturing process is complicated. The resulting exhaust buffer chamber is heavy and expensive to produce. In addition, copper conducts heat rapidly, and further reduces compressor cooling efficiency when coupled with the high temperature inside the compressor.